There has been developed a system of displaying two or more mixed pictures on one display plane potentially having an image separation mechanism to take out each of given original images by the image separation mechanism. Such a system includes a method of separately presenting each of two images with binocular disparity between them to each of the right and left eyes in a two-dimensional image to reproduce a three-dimensional image, or a double-view display displaying multi-views from one displayed face, or the like.
In the image separation mechanism used in the above-described system, the mixed pictures are separated by adopting an image separation filter using linearly polarized light rays crossing at right angles, circularly polarized light rays, wavelengths different from each other (red and blue etc.), or the like. Although the above-described image separation filter can be formed in a pixel on the display plane, it is difficult to make such a filter. Thus, a method is often used in which the image separation filter is provided on the outside of an ordinary display element displaying a two-dimensional image.
Namely, there is known a method of, for example, affixing a half-wave plate for each line outside a polarizing plate (U.S. Pat. Nos. 5,264,964, 5,327,285, and 5,537,144) (SID91DIGEST 840).
In FIG. 20, there are shown cross sectional views of a display device capable of expressing a first image and a second image alternately on lines on one display plane when being watched. The FIG. 20 shows an example of a transparent type display device having a light source provided behind the display plane with arrows in the figure representing light beams watched by a watcher. In general, a pixel member 1 of a liquid crystal display element of an LCD is arranged to be put between transparent materials such as glasses 2a and 2b with an image separation filter 3 to be mounted at a specified distance apart from the pixel member 1 as shown in the figures.
The above-described pixel member 1 has an arrangement in which a first image region (a pixel region displaying the first image) s1 and a second image region (a pixel region displaying the second image) s2 are alternately formed, and the image separation filter 3 has an arrangement in which a first image separation mechanism e1 and a second image separation mechanism e2 are alternately formed.
FIG. 20A shows an example of the width of the image separation filter 3 and the width of the pixel 1 being out of matching with each other, FIG. 20B shows an example of the position of the image separation filter 3 being out of matching, and FIG. 20C shows an example of light from the light source (not shown) to a watcher being out of matching with the pixel 1 and the image separation filter 3.
As is apparent from FIG. 20, a light beam, emitted from the light source and passing through the first image separation mechanism toward the watcher, must pass through the first image region. However, the light beam, the position of the pixel, the position and the width of the separation filter, being out of matching with one another, allow a part of the light beam to pass through the second image region as indicated by x mark. This caused a problem of preventing the image from being separated, that is, generating crosstalk. This is the same about a light beam emitted from the light source and passing through the second image separation mechanism.